Scholarlink

<p>Arsenic-bearing gypsum (ABG) is a typical hazardous solid waste generated from the non-ferrous metal smelting industry. In this study, corn stover, a common agricultural waste, was used as a co-pyrolysis substrate for arsenic (As) removal and immobilization from ABG. The effects of corn stover dosage, pyrolysis temperature, dosage of the auxiliary reagent (i.e., sulfuric acid), and reaction time on As removal efficiency from ABG, along with the corresponding synergistic mechanisms, were systematically explored. Under optimized conditions (corn stover/ABG mass ratio = 2:1, 750&#xa0;°C, sulfuric acid dosage = 0.4&#xa0;mL/g, reaction time = 240&#xa0;min), the total As content in the pyrolysis product was reduced to 0.63% (from an initial 6.47% in raw ABG), and the As leaching concentration decreased to as low as 0.50&#xa0;mg/L, which is well below the Chinese regulatory limit of 5&#xa0;mg/L for non-hazardous waste disposal. Sequential extraction results revealed that the residual As was primarily present in the stable residual fraction. The analyses of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) revealed the synergistic mechanisms of As removal and immobilization from ABG during co-pyrolysis, including As reductive volatilization to As₂O₃ by CO/H₂ derived from corn stover pyrolysis, adsorption and trapping by porous biochar, and transformation into stable compounds such as As₂S₃, which were promoted by sulfuric acid and high temperature. This study develops an efficient and low-cost “waste-to-treat-waste” strategy, providing new insights into the safe disposal of ABG, significantly reducing environmental risks, and offering a feasible solution for the treatment of similar hazardous wastes.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Waste-to-Treat-Waste: Arsenic Removal and Immobilization of Arsenic-Bearing Gypsum Via Co-Pyrolysis with Corn Stover

  • 期刊论文

  • 发表日期：

    2026年6月15日

查看全文
  • Guoliang Chen,
  • Zhicheng Xie,
  • Teng Mao,
  • Kaixin Liu,
  • Jiacheng Qiao,
  • Zhang Chen,
  • Zhixian Li,
  • Jianlin Zhou

摘要

Arsenic-bearing gypsum (ABG) is a typical hazardous solid waste generated from the non-ferrous metal smelting industry. In this study, corn stover, a common agricultural waste, was used as a co-pyrolysis substrate for arsenic (As) removal and immobilization from ABG. The effects of corn stover dosage, pyrolysis temperature, dosage of the auxiliary reagent (i.e., sulfuric acid), and reaction time on As removal efficiency from ABG, along with the corresponding synergistic mechanisms, were systematically explored. Under optimized conditions (corn stover/ABG mass ratio = 2:1, 750 °C, sulfuric acid dosage = 0.4 mL/g, reaction time = 240 min), the total As content in the pyrolysis product was reduced to 0.63% (from an initial 6.47% in raw ABG), and the As leaching concentration decreased to as low as 0.50 mg/L, which is well below the Chinese regulatory limit of 5 mg/L for non-hazardous waste disposal. Sequential extraction results revealed that the residual As was primarily present in the stable residual fraction. The analyses of X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) revealed the synergistic mechanisms of As removal and immobilization from ABG during co-pyrolysis, including As reductive volatilization to As₂O₃ by CO/H₂ derived from corn stover pyrolysis, adsorption and trapping by porous biochar, and transformation into stable compounds such as As₂S₃, which were promoted by sulfuric acid and high temperature. This study develops an efficient and low-cost “waste-to-treat-waste” strategy, providing new insights into the safe disposal of ABG, significantly reducing environmental risks, and offering a feasible solution for the treatment of similar hazardous wastes.